Knowledge of Jupiter's innards is scarce, mostly coming from the Galileo probe, which in 1995 plunged 100 miles into the Jovian atmosphere and relayed data until it vaporized an hour later. But here's what we know: First, any spacecraft would need to make it through Jupiter's instrument-scrambling radiation belts, the harshest of which extend 200,000 miles from the planet. Then it would face winds of up to 230 mph tearing across the surface of the planet's turbulent hydrogen-cloud atmosphere and, if it survived those, gusts of nearly 400 mph starting about 28 miles into the atmosphere. In the first 100 miles, temperatures run to around 306°F, and scientists suspect that it's up to 50,000° closer to the core. The atmosphere likely ripped apart the 1.2-mile-wide Shoemaker-Levy 9 comet when it hit Jupiter back in 1994. Just saying.